Question

Food can be kept for long periods of time by adding salt or sugar, because these substances

• A. Make the food too acidic for spoilage to occur
• B. Bind to water, thereby making it unavailable to the microorganisms
• C. Effectively kills microorganisms
• D. Dissolve the cell walls in plant foods

Answer 1

Answer: (B)

Bind to water, thereby making it unavailable to the microorganisms

Salt and sugar are the effective preservatives because it reduces the water activity of foods. The water activity of a food or the availability of water in food that supports the microbial growth and chemical reactions. Adding salt or sugar to foods can cause microbial cells to undergo osmotic shock, resulting in the loss of water from the cell and thereby causing cell death or retarded growth. For some microorganisms, salts of sugar bind to the water and make it unavailable to the microorganism that causes microbial cell death due to lack of moisture.

Therefore, the correct answer is option B.